The present invention relates to a method and an apparatus for connection with a tubing string for use in a wellbore for regulating the flow of a fluid within a wellbore annulus between the tubing string and the wellbore. Preferably, the invention is used for selective steam injection of a desired hydrocarbon producing zone within an underground formation or for isolating the wellbore annulus to prevent heat loss when injecting down the tubing string.
Wellbore packers are typically suspended in a wellbore from a tubing string or other pipe extending to the surface. These packers are employed for providing a downhole seal between the tubing string and the surrounding wellbore in order to prevent the flow of fluids through an annulus defined between the tubing string and the wellbore. Such packers are desirable for a number of uses, including providing a seal or barrier such that fluid may be selectively injected to or at a desired level in the wellbore to a desired zone within the surrounding formation.
For instance, a zone may be isolated for steaming by pulling the tubing string and installing one or more packer cup along the tubing string at predetermined positions. When top zone steaming of a formation is required, one or more packer cups is installed along the tubing string such that the packer cups are located below the zone to be steam injected when the tubing string is run back into the wellbore. Steam is then directed through the wellbore annulus. The packer cup provides a seal between the tubing string and the wellbore and prevents the steam from passing through the wellbore annulus below the desired zone.
When an intermediate or middle zone is desired to be isolated for steaming, the cups are employed in a straddle application. Specifically, packer cups are installed along the tubing string such that the packer cups are located above and below the zone to be isolated when the tubing string is run back into the wellbore. Further, for steam injection, a perforated joint of pipe is installed between the packer cups. The steam is injected through the tubing string with the downhole pump seated and exits the tubing string through the perforated joint into the wellbore annulus at the desired level. The packer cups again provide a seal between the tubing string and the wellbore and maintain the steam within the desired level of the wellbore annulus such that the steam is directed into the desired zone of the formation.
When the lower or bottom zone is desired to be isolated for steaming, the packer cups are located above the zone to be steamed and the steam is injected through the tubing string with the downhole pump unseated or removed.
In any case, once the formation has been steamed, the tubing string must again be pulled from the wellbore so that the packer cups may be removed. Once removed, a pump is installed and the tubing string is run back into the wellbore to permit production of the well. Specifically, production from all zones is permitted to commingle and flow down to the pump for pumping from the well.
Often in wells that have only one zone, the wells are steamed down the tubing string and a wellbore packer or packer cups are used to prevent steam from entering or refluxing in the wellbore annulus. Steam flow or reflux in the wellbore annulus results in heat loss to the well casing, cement and earth. Again, following steaming, the wellbore packer must be removed for the production cycle in order to allow produced gases to flow up the wellbore annulus.
U.S. Pat. No. 3,701,382 issued Oct. 31, 1972 to Williams, U.S. Pat. No. 3,897,824 issued Aug. 5, 1975 to Fisher, U.S. Pat. No. 4,151,875 issued May 1, 1979 to Sullaway, and U.S. Pat. No. 3,420,305 issued Jan. 7, 1969 to Alexander et. al. each describe a wellbore packer which is fixed in position within the wellbore through release of a releasable connection, and in particular, through shearing of a shearing element. Typically, shearing occurs upon vertical reciprocation of the tubing string.
For example, Williams describes a packer which is held in a retracted position, while lowering into the wellbore, by shearable screws or pins. The screws or pins are sheared when relative upward movement or upstrain of a packer body with respect to the mandrel is effected. To remove the packer, a downward relative movement is applied to move the packer back to the retracted position. However, since the releasable connection, i.e. shear pin, has been broken, further means are required to lock the packer in the locked position. It is thus clear that the packer may not be repeatedly used for multiple operations without removing the packer from the wellbore between uses and replacing the releasable connection.
As indicated, the above described wellbore packers require pulling of the tubing string either to remove the wellbore packer in order to permit fluids to subsequently flow through the wellbore annulus or to replace or refit the wellbore packer for repeated uses. Pulling the tubing string and either replacing or removing the wellbore packer is both time consuming and costly.
Therefore, it is desirable for the packer to be releasable and returnable to an open position to permit multiple operations or uses. In other words, the packer is preferably capable of being both set or closed and unset or opened from the surface for any number of uses without the need to pull the tubing string. In its closed condition, the wellbore annulus is sealed. In its open condition, the packer permits fluid to flow through the wellbore annulus from above the packer to below the packer and vice versa. Further, in its open condition, the packer may be moved to a new desired location in the wellbore, where it may be reset or closed for further use.
As a result, wellbore packers have been developed which provide expandable and retractable packing elements. To seal the wellbore annulus, the packing elements are expanded or extended radially outwards for engagement with the wellbore. More particularly, the packing element is compressed longitudinally within the wellbore to cause lateral expansion of the packing element with sufficient pressure to seal against the wellbore. However, it has been found that after being compressed for an extended period of time that the packing element may not return to its original condition upon release of the longitudinal compression. As a result, the compressed packing element may remain in a sealing condition or it may otherwise interfere with the subsequent passage of fluid through the wellbore and thus, may need to be removed or replaced.
Thus, although these packers may be closed and opened from the surface any number of times as necessary for the desired application, the packer, including the packing element, may impede or otherwise interfere with the flow of fluid through the wellbore annulus. Thus, wellbore packers have been developed which provide a bypass passageway to allow fluid to pass by the packing element. The bypass passageway is typically associated with a bypass valving mechanism for opening and closing the bypass passageway as desired.
However, these bypass passageways tend to be relatively narrow in that the flow paths provided for the fluid flow are too small, which restricts the flow of fluid through the wellbore annulus. Thus, a fully satisfactory response is not provided to the need for a relatively unrestricted flow through the annulus. As well, these relatively small passageways have a tendency to become plugged or clogged by sand and other particulate matter contained within the wellbore fluids.
Further, as indicated, the valving mechanism or structure provided for the bypass passageway is separate from the mechanism or structure provided for actuation of the packing element. In other words, two distinct sealing mechanisms, actuated independently, are provided for the bypass passageway and the packing element. As a result, the overall structure of the packer is relatively complex.
Finally, many wellbore packers which are capable of being selectively opened and closed from the surface are so actuated through manipulation of the tubing string, and specifically, the weight applied through the tubing string to the wellbore packer. These weight setting packers specifically employ the weight of the tubing string above the packer to manipulate the packing elements, and the packer valve associated with the bypass passageway, to a sealed position.
More particularly, these packers tend to be manipulated through longitudinal movement of the tubing string or a combination of longitudinal and rotational movement of the tubing string. As discussed above, the application of sufficient weight to the packing element causes compression of the packing element such that it extends for engagement with the wellbore. Further, the application of sufficient weight causes sealing of the bypass passageway. In addition, the longitudinal and rotational movement are often controlled through the use of a relatively complex structural mechanism, such as a mechanism comprising a J-slot and corresponding lug arrangement.
In any event, difficulties may be encountered in controlling the amount of weight applied through the tubing string to the packing element. The application of excessive weight, particularly for extended periods of time, tends to damage the packing elements and cause longitudinal slippage of the packer within the wellbore. Thus, such packers are often employed in combination with slippage devices for controlling longitudinal movement of the packer within the wellbore. In addition, depending upon the manner of sealing the bypass passageway, this seal may also be subjected to excessive compressive loading, thereby reducing the life of the seal and possibly leading to seal failure.
Examples of these types of wellbore packers are provided by U.S. Pat. No. 3,467,184 issued Sep. 16, 1969 to Young, U.S. Pat. No. 3,570,596 issued Mar. 16, 1971 to Young, U.S. Pat. No. 3,645,334 issued Feb. 29, 1972 to McGill, U.S. Pat. No. 3,785,436 issued Jan. 15, 1974 to Davis, Jr., U.S. Pat. No. 4,071,084 issued Jan. 31, 1978 to Brown et. al., U.S. Pat. No. 4,506,736 issued Mar. 26, 1985 to Evans and U.S. Pat. No. 4,627,491 issued Dec. 9, 1986 to Zunkel.
Each of these examples describes a packer including a tubular body mounted about a mandrel. The tubular body comprises one or more packing elements mounted about an outer surface of the tubular body between a downwardly facing shoulder and an upwardly facing shoulder of the tubular body. Downward movement of the mandrel relative to the tubular body moves the downwardly and upwardly facing shoulders of the tubular body together into closer proximity such that the packing elements are compressed between the shoulders. Compression of the packing elements between the shoulders of the tubular body causes the packing elements to expand radially outward for engagement with the wellbore. Engagement of the packing elements with the wellbore seals the annular space therebetween.
The packer also defines a narrow bypass passageway between an inner surface of the tubular body and the mandrel. A separate downward movement of the tubular body relative to the mandrel results in the coming together or engagement of a seal surface on the mandrel with a seal on the inner surface of the tubular body. Engagement of the seal surface and the seal acts to seal the upper end of the bypass passageway. The bypass passageway may be sealed either before or after the sealing of the wellbore annulus by the packer elements. In either case, the downward weight or compressive force must be maintained in order to maintain the sealing engagement of the packer elements with the wellbore and the sealing engagement of the seal surface with the seal.
Accordingly, each of these patents is not fully satisfactory as each one suffers from one or more of the difficulties or disadvantages discussed above.
Thus, there remains a need in the industry for an improved apparatus for connection with a tubing string for use in a wellbore for regulating the flow of fluid in a wellbore annulus between the tubing string and the wellbore. In particular, there is a need for an improved apparatus capable of being opened and closed from the surface, to either permit flow through or to seal the wellbore annulus respectively, so that pulling of the tubing string from the wellbore is not required. In addition, there is a need for a relatively simple or easily operably mechanism for the actuation of the apparatus from the surface, as compared with known wellbore packers.
Further, there is a need for the apparatus to permit flow through the wellbore annulus relatively unrestricted or unimpeded as compared with other wellbore packers when the apparatus is in the open position. In other words, there is a need for an apparatus which provides for bypassing of the apparatus in a manner which does not significantly interfere with or impede the flow of the fluid between a position above the apparatus and a position below the apparatus in the wellbore.
The present invention relates to an apparatus for connection with a tubing string for use in a wellbore for regulating the flow of fluid in a wellbore annulus between the tubing string and the wellbore. In addition, the present invention relates to a method for regulating the flow of a fluid in the wellbore annulus. The method is preferably performed using the apparatus of the within invention.
The apparatus is comprised of at least one packer valve for regulating the flow through the wellbore annulus. Although the apparatus and the packer valve may be used for any application in which the flow of fluid through the wellbore annulus requires regulation, such as for isolating the perforations while hot oiling or de-waxing of the tubing string, the within invention is particularly suited for use in the steam injection of a hydrocarbon producing formation. More particularly, the apparatus may be used for isolating a particular desired zone of the formation so that the desired zone is selectively steamed during performance of the steaming operation.
Where an upper zone or a lower zone of the formation is to be steamed, the apparatus comprises the packer valve as described herein. Alternately, the apparatus may comprise two packer valves and a tubing valve connected together in series such that the tubing valve is located therebetween. In this configuration, the apparatus is particularly useful for isolating a middle or intermediate zone of the formation so that the intermediate zone may be selectively steamed during the steaming operation.
In particular, the apparatus may also be used to isolate all of the wellbore annulus above the desired zone to be steamed in order to keep steam out of this annulus, thus reducing heat loss to the wellbore wall, casing wall or surrounding cement and earth.
In any case, the apparatus is preferably capable of being actuated from the surface so that pulling of the tubing string from the wellbore is not required to operate the apparatus. More particularly, the packer valve of the apparatus is preferably movable between an open flow position, permitting flow through the wellbore annulus, and a closed flow position, regulating or restricting the flow of fluid through the annulus. The packer valve may be moved or actuated between the open and closed flow positions in any manner and by any mechanism or structure permitting the operation of the packer valve from the surface. However, preferably, the packer valve is actuated through the tubing string. Specifically, the packer valve is preferably connectable to the tubing string such that the packer valve is manipulable, and actuatable, through manipulation of the tubing string.
The tubing string may be manipulated in any manner to actuate the packer valve. For instance, the tubing string may be longitudinally or axially moved in the wellbore in either an upwards or downwards direction. However, preferably, the tubing string is rotated at the surface to actuate the apparatus. The tubing string may be rotated by any device, mechanism or method, including manual rotation, able to rotate the tubing string in the wellbore in the desired direction of rotation. However, preferably, the tubing string is rotated by a tubing rotator provided at the surface for rotating the tubing string within the wellbore. Any tubing rotator able to rotate the tubing string within the wellbore may be used for this purpose.
Further, the apparatus, including the packer valve, preferably permits a flow of fluid through the wellbore annulus relatively unrestricted or unimpeded as compared with other wellbore packers when the packer valve is in the open flow position. Specifically, the packer valve provides a fluid flow path for bypassing the packer valve which restricts or impedes the flow of the fluid through the wellbore annulus in a relatively less substantial manner or in a relatively lesser degree as compared to other wellbore packers.
In particular, the packer valve preferably defines an outer annular space between the packer valve and the wellbore when positioned in the wellbore and an inner annular space. In the open flow position, the outer annular space communicates with the inner annular space to provide the fluid flow path between a position above the packer valve and a position below the packer valve. In the closed flow position, communication between the outer and inner annular spaces is restricted to regulate the flow through the fluid flow path or between the inner and outer annular spaces.
The invention is comprised of an apparatus for connection with a tubing string for use in a wellbore for regulating the flow of a fluid within a wellbore annulus between the tubing string and the wellbore. In a first aspect of the invention in its apparatus form, the apparatus is comprised of:
(a) a tubing rotator for rotating the tubing string within the wellbore; and
(b) at least one packer valve for connection with the tubing string, wherein the packer valve is actuatable through rotation of the tubing string by the tubing rotator;
wherein rotation of the tubing string by the tubing rotator actuates the packer valve between a closed flow position wherein the packer valve substantially seals the wellbore annulus and an open flow position wherein the flow of the fluid is permitted through the wellbore annulus.
The tubing rotator may be comprised of any tubing rotator able to rotate the tubing string within the wellbore as required to actuate the packer valve. Further, in this aspect of the apparatus, the packer valve may be comprised of any packer valve able to regulate the flow of fluid through the wellbore annulus, which is able to be connected downhole with the tubing string and which is actuatable through rotation.
Preferably, rotation of the tubing string in a first direction actuates the packer valve to the closed flow position and rotation of the tubing string in a second opposed direction actuates the packer valve to the open flow position. In addition, the packer valve is preferably comprised of:
(a) a packer body for connection with the tubing string such that the packer body is actuatable through rotation of the tubing string by the tubing rotator, wherein the packer body has a longitudinal bore extending therethrough for communication with the tubing string;
(b) an inner packing member associated with the packer body such that the inner packing member extends radially outwardly from the packer body, wherein an outer annular space is defined between the inner packing member and the wellbore when the packer valve is positioned in the wellbore;
(c) an outer packing member associated with the packer body such that the outer packing member is movable axially relative to the inner packing member upon rotation of the tubing string, wherein the outer packing member is a spaced radial distance from the packer body to define an inner annular space therebetween for bypassing the outer packing member;
wherein the outer packing member is movable axially relative to the inner packing member between the closed flow position wherein the outer packing member is engaged with the inner packing member and the wellbore to substantially seal the outer annular space and the inner annular space and the open flow position wherein the outer packing member is disengaged from at least the inner packing member and the outer annular space communicates with the inner annular space to permit the flow of the fluid through the outer annular space and the inner annular space.
In a second aspect of the invention in its apparatus form, the apparatus comprises at least one packer valve. In this aspect of the invention, the packer valve comprises:
(a) a packer body for connection with the tubing string such that the packer body is manipulable through manipulation of the tubing string, wherein the packer body has a longitudinal bore extending therethrough for communication with the tubing string;
(b) an inner packing member associated with the packer body such that the inner packing member extends radially outwardly from the packer body, wherein an outer annular space is defined between the inner packing member and the wellbore when the packer valve is positioned in the wellbore;
(c) an outer packing member associated with the packer body such that the outer packing member is movable axially relative to the inner packing member, wherein the outer packing member is a spaced radial distance from the packer body to define an inner annular space therebetween for bypassing the outer packing member;
wherein the inner packing member is movable axially relative to the outer packing member between a closed flow position wherein the outer packing member is engaged with the inner packing member and the wellbore to substantially seal the outer annular space and the inner annular space and an open flow position wherein the outer packing member is disengaged from at least the inner packing member and the outer annular space communicates with the inner annular space to permit the flow of the fluid through the outer annular space and the inner annular space.
In the second aspect of the apparatus, the packer valve may be actuated by manipulation of the tubing string in any manner, such as by longitudinal movement of the tubing string resulting in a longitudinal or axial movement of the inner packing member relative to the outer packing member. Specifically, longitudinal movement of the tubing string in a first direction may cause the inner packing member to move axially relative to the outer packing member towards the closed flow position, while longitudinal movement in an opposed second direction may cause the inner packing member to move axially relative to the outer packing member towards the open flow position.
However, preferably in both the first and second aspects of the invention, the packer valve is actuated by rotation of the tubing string. Specifically, rotation of the tubing string in a first direction causes the inner packing member to move axially relative to the outer packing member towards the closed flow position and rotation of the tubing string in a second opposed direction causes the inner packing member to move axially relative to the outer packing member towards the open flow position. More particularly, rotation of the tubing string rotates the inner packing member relative to the outer packing member and rotation of the inner packing member relative to the outer packing member is translated into axial movement of the inner packing member relative to the outer packing member.
In the first and second aspects, the inner packing member may be comprised of any packing device, element or structure, and may have any shape or configuration, able to sealingly engage the outer packing member. Similarly, the outer packing member may be comprised of any packing, device, element or structure, and may have any shape or configuration, able to sealingly engage the inner packing member and the wellbore. Further, the inner and outer packing members are preferably shaped or configured to maximize a radial dimension of the outer annular space and a radial dimension of the inner annular space respectively.
The inner and outer annular spaces may each have any radial dimension which permits the necessary engagement of the inner packing member and the outer packing member and the necessary engagement of the outer packing member and the wellbore. Further, the inner and outer annular spaces may have any relative radial dimensions. In the preferred embodiment, the radial dimension of the outer annular space is about equal to the radial dimension of the inner annular space in the open flow position.
Further, the inner packing member and the outer packing member define a location of contact in the closed flow position. Preferably, in the closed flow position the inner packing member overlaps with the outer packing member. In other words, an outer surface of the inner packing member and an inner surface of the outer packing member engage such that the location of contact therebetween has a radial dimension. In the preferred embodiment, the radial dimension of the location of contact is minimized while still permitting the sealing engagement therebetween. Minimization of the radial dimension of the location of contact assists in the maximization of the radial dimensions of the inner and outer annular spaces.
Although the outer packing member may have any shape or configuration and may sealingly engage the inner packing member and the wellbore in any manner, the outer packing member preferably comprises a first surface for sealingly engaging the wellbore and a second surface for sealingly engaging the inner packing member in the closed flow position. Further, the engagement of the second surface of the outer packing member with the inner packing member preferably moves the outer packing member radially outwardly to sealingly engage the first surface of the outer packing member with the wellbore.
Further, the sealing engagement between the inner and outer packing members and between the outer packing member and the wellbore may be accomplished by one or more sealing members located between the respective surfaces. Specifically, at least one sealing member is preferably associated with the first surface of the outer packing member for sealingly engaging the wellbore and at least one sealing member is preferably associated with at least one of the second surface of the outer packing member and the inner packing member for sealingly engaging the inner packing member and the outer packing member. Each sealing member may be comprised of any seal, sealing device, mechanism or structure.
The packer body may be comprised of any type and number of elements or members permitting the association of the inner and outer packing members therewith in the manner described. In addition, each of the inner and outer packing members may be associated with the packer body by any manner of connection or mounting permitting the relative axial movement therebetween between the open flow and closed flow positions.
However, preferably, the packer body is comprised of a packer mandrel for connection with the tubing string such that the packer mandrel is rotatable through rotation of the tubing string. The packer mandrel has an outer surface and a longitudinal bore extending therethrough for communication with the tubing string. Preferably, the inner packing member is mounted about the packer mandrel such that the inner packing member extends radially outwardly from the outer surface of the packer mandrel.
In addition, the packer valve is preferably further comprised of a packer sleeve mounted about the packer mandrel such that rotation of the packer mandrel relative to the packer sleeve is translated into axial movement of the packer mandrel relative to the packer sleeve. Further, the outer packing member is mounted with the packer sleeve so that the inner packing member is movable axially relative to the outer packing member upon axial movement of the packer mandrel relative to the packer sleeve.
Any structure or mechanism may be used for translating the relative rotational movement into relative axial movement. In the preferred embodiment, the outer surface of the packer mandrel comprises an outer threaded portion and the packer sleeve has an inner surface comprising an inner threaded portion. The outer threaded portion of the packer mandrel is engaged with the inner threaded portion of the packer sleeve such that rotation of the packer mandrel relative to the packer sleeve is translated into axial movement of the packer mandrel relative to the packer sleeve.
In order to facilitate the relative rotation between the inner packing member and the outer packing member, the apparatus is preferably further comprised of a drag member associated with the outer packing member for engaging the wellbore to inhibit rotation of the outer packing member within the wellbore upon rotation of the inner packing member. The drag member may be a separate unit or element from the outer packing member or it may be integrally formed with the outer packing member to form a single unit or unitary member. Further, it may be associated with the outer packing member in any manner permitting it to inhibit the rotation of the outer packing member within the wellbore. In the preferred embodiment, both the outer packing member and the drag member are mounted with the packer sleeve.
Any drag member or drag structure able to inhibit the rotation of the packer sleeve may be used. For instance, the drag member may be comprised of one or more bow springs extended from the packer sleeve for engagement with the wellbore. However, in the preferred embodiment, the drag member is comprised of a plurality of drag blocks having an inner surface and an outer surface for engaging the wellbore and at least one spring associated with the inner surface of each drag block for urging the drag block radially outward such that the outer surface is urged into engagement with the wellbore. Further, each drag block may be pivotable to a binding position upon the rotation of the inner packing member relative to the outer packing member in the first direction in order to prevent rotation of the outer packing member within the wellbore. Further, the drag block may be associated with a cam surface of the inner packing member which will urge the drag block into engagement with the wellbore.
In addition, the apparatus may be further comprised of a tubing valve for permitting fluid to flow between the longitudinal bore of the packer body, and in particular the longitudinal bore of the packer mandrel, and the wellbore annulus. The tubing valve may be actuated in any manner and by any mechanism or structure. Preferably, the tubing valve is actuatable from the surface and more preferably, is actuatable through manipulation of the tubing string, and more preferably, through rotation of the tubing string. As well, the tubing valve is preferably open when the packer valve is in the closed flow position and is preferably closed when the packer valve is in the open flow position.
Preferably, axial movement of the inner packing member relative to the outer packing member to the closed flow position opens the tubing valve to permit the passage of fluid therethrough and axial movement of the inner packing member relative to the outer packing member to the open flow position closes the tubing valve to prevent the passage of fluid therethrough. In the preferred embodiment, axial movement of the packer mandrel relative to the packer sleeve to the closed flow position opens the tubing valve, while axial movement of the packer mandrel relative to the packer sleeve to the open flow position closes the tubing valve.
The tubing valve may be comprised of any valve or valving device able to selectively permit and restrict the flow of the fluid therethrough. In the preferred embodiment, the tubing valve is comprised of a tubing mandrel and a tubing valve. The tubing mandrel has a longitudinal bore extending therethrough and is connected with the packer mandrel such that the longitudinal bore of the tubing mandrel communicates with the longitudinal bore of the packer mandrel and such that axial movement of the packer mandrel causes axial movement of the tubing mandrel. The tubing mandrel defines at least one mandrel aperture therethrough for the passage of fluid from the longitudinal bore.
The tubing sleeve is mounted about the tubing mandrel such that the tubing mandrel is movable axially relative to the tubing sleeve. Further, the tubing sleeve is connected to the packer sleeve such that axial movement of the packer sleeve causes axial movement of the tubing sleeve. The tubing sleeve defines at least one sleeve aperture therethrough for the passage of fluid which is communicable with the mandrel aperture upon the axial alignment of the mandrel aperture and the sleeve aperture. Movement of the packer valve towards the closed flow position axially aligns the mandrel aperture and the sleeve aperture to permit the passage of fluid therethrough, while movement of the packer valve towards the open flow position axially misaligns the mandrel aperture and the sleeve aperture to inhibit the passage of fluid therethrough.
Finally, the apparatus may be comprised of two packer valves connected together in series with the tubing valve such that the tubing valve is located therebetween. Preferably, rotation of the tubing string in the first direction causes each of the packer valves to move towards the closed flow position while the tubing valve is moved towards an open position and rotation of the tubing string in the second direction causes each of the packer valves to move towards the open flow position while the tubing valve is moved towards a closed position.
In addition, the invention is comprised of a method for regulating the flow of a fluid in a wellbore within a wellbore annulus between a tubing string and the wellbore. In a first aspect of the invention in its method form, the method is for use with a tubing rotator for rotating the tubing string within the wellbore and the method is comprised of the steps of:
(a) rotatably suspending the tubing string in the wellbore;
(b) connecting at least one packer valve with the tubing string, wherein the packer valve is actuatable through rotation of the tubing string between a closed flow position wherein the packer valve substantially seals the wellbore annulus and an open flow position wherein the flow of the fluid is permitted through the wellbore annulus; and
(c) rotating the tubing string by the tubing rotator in a first direction to actuate the packer valve to the closed flow position.
In this first aspect, the method may further comprise the step of rotating the tubing string in a second opposed direction to actuate the packer valve to the open flow position.
In a second aspect of the invention in its method form, the method is comprised of the steps of:
(a) providing at least one packer valve comprising a packer body, an inner packing member and an outer packing member;
(b) suspending the packer body from the tubing string such that the packer body is manipulable through manipulation of the tubing string, wherein the packer body has a longitudinal bore extending therethrough for communication with the tubing string and wherein the inner packing member is associated with the packer body such that the inner packing member extends radially outwardly from the packer body, wherein an outer annular space is defined between the inner packing member and the wellbore when the packer valve is positioned in the wellbore;
(c) mounting the outer packing member with the packer body such that the outer packing member is movable axially relative to the inner packing member, wherein the outer packing member is a spaced radial distance from the packer body to define an inner annular space therebetween for bypassing the outer packing member;
(d) first moving the inner packing member axially towards the outer packing member to a closed flow position wherein the outer packing member is engaged with the inner packing member and the wellbore to substantially seal the outer annular space and the inner annular space.
In this second aspect, the method may further comprise the step of second moving the inner packing member axially away from the outer packing member to an open flow position wherein the outer packing member is disengaged from at least the inner packing member and the outer annular space communicates with the inner annular space to permit the flow of the fluid through the outer annular space and the inner annular space.
In the first aspect, the tubing string is rotated in order to actuate the packer valve. In the second aspect, the first and second moving steps require the axial movement of the inner packing member relative to the outer packing member. This relative axial movement may be accomplished in any manner, such as through longitudinal or axial movement of the tubing string, through a rotary movement of the tubing string or through a combination thereof. However, preferably, the first and second moving steps are accomplished through rotation of the tubing string.
Specifically, the first moving step is preferably comprised of:
(a) rotating the tubing string in a first direction to rotate the inner packing member in the first direction relative to the outer packing member; and
(b) translating the rotation of the inner packing member relative to the outer packing member into axial movement of the inner packing member relative to the outer packing member towards the closed flow position.
Further, the second moving step is preferably comprised of:
(a) rotating the tubing string in a second direction to rotate the inner packing member in the second direction relative to the outer packing member; and
(b) translating the rotation of the inner packing member relative to the outer packing member into axial movement of the inner packing member relative to the outer packing member towards the open flow position.
Preferably, the method further comprises the step of inhibiting the rotation of the outer packing member within the wellbore during rotation of the tubing string in the first direction to facilitate rotation of the inner packing member relative to the outer packing member. More preferably, the method comprises the step of inhibiting the rotation of the outer packing member within the wellbore during rotation of the tubing string in the first direction and the second direction to facilitate rotation of the inner packing member relative to the outer packing member.
In addition, the method may further comprise of the steps of:
(a) providing a tubing valve for permitting fluid to flow between the longitudinal bore of the packer body and the wellbore annulus;
(b) opening the tubing valve to permit the flow of the fluid therethrough upon movement of the packer valve to the closed flow position; and
(c) closing the tubing valve to inhibit the passage of the fluid therethrough upon movement of the packer valve to the open flow position.
Finally, the method may be comprised of providing two packer valves connected together in series with the tubing valve such that the tubing valve is located therebetween, wherein rotating the tubing string in the first direction causes each of the packer valves to move towards the closed flow position while the tubing valve is moved towards an open position and rotating the tubing string in the second direction causes each of the packer valves to move towards the open flow position while the tubing valve is moved towards a closed position.
As indicated above, the method is preferably performed using the apparatus, and in particular, the elements or components of the apparatus as described above. However, any other suitable apparatus, or elements or components of it, may be used which permit the performance of the method as described herein.